How many functional factors does it take to explain perceptual learning?
” Perception 31 ECVP Abstract Supplement How many functional factors does it take to explain perceptual learning? B S Tjan, S T L Chung, D M Levi Performance for many visual tasks improves with practice. We reported that improvements in identifying letters in peripheral vision is due to an increase in sampling efficiency, and not a reduction in intrinsic noise (Chung et al, 2001 Investigative Ophthalmology & Visual Science 42 Supplement, 3931). These two factors of the linear-amplifier model (LAM) depend on criterion d’. Here, we examine the functional nature of perceptual learning in a criterion-independent manner by using the perceptual template model (PTM, Lu and Dosher, 1999 Journal of the Optical Society of America A 16 764 – 778). PTM extends LAM by adding transducer nonlinearity and multiplicative noise. Psychometric functions for identifying single letters embedded in 6 external-noise levels were collected over 6 days of practice. Contrast thresholds at d’ = 0.8, 1.7, 2.7 were
